1. Technical Field
The present disclosure relates to cannulated surgical instruments. More particularly, the present disclosure relates to surgical instruments or implants used in conjunction with guidewires having enlarged heads, and to methods for using the same.
2. Brief Description of the Related Art
Rods or nails are used in a variety of surgical procedures, such as to treat fractures of long bones in the body. For example, an intramedullary (or “IM”) rod or nail is a metal rod that can be inserted into the medullary cavity of a bone to bridge a fracture and aid in the healing process.
In one surgical technique used for intramedullary nail implantation, a guidewire with a spherical or ball tip is surgically introduced to the medullary cavity of a bone to bridge a fracture. A guidewire tube is then passed over the inserted ball tip guide wire. With the guidewire tube now bridging the fracture gap, the ball tip guidewire is removed from the tube and medullary cavity. A smooth guidewire is then inserted into the hollow guidewire tube, and the tube is removed to leave only the smooth guidewire in the medullary cavity of the bone. The smooth guidewire can then be used to guide an intramedullary nail into the medullary cavity by passing the cannula of the nail over the smooth wire as the nail is inserted. Once the nail is properly placed and secured, the smooth guidewire is removed through the nail cannula. This technique may be referred to as a “wire exchange” technique because the ball tip guidewire is exchanged for the smooth guidewire before insertion of the IM nail.
This wire exchange technique is typically performed because the size of the cannula in a traditional intramedullary nail is insufficient to allow passage of the enlarged head of a ball tip guidewire through the cannula. In a recent generation of intramedullary nails, however, improved designs and materials may allow for a larger nail cannulation which is sufficient to allow an enlarged head or ball tip of a guidewire to pass therethrough. Because the nail cannula is smaller than a typical guidewire tube, these recent designs may result in the ball tip becoming stuck or “hung up” when the shoulder between the ball tip and the wire shaft of the guidewire engages a lip or sharp edge of the distal terminus of the cannula.
To prevent the possibility of the ball tip guidewire becoming stuck as it is pulled proximally into the cannula, a surgeon may choose to perform a “wire exchange,” thereby foregoing a savings in time that would result from using the ball tip guidewire as the guidewire for the intramedullary nail. Conversely, a surgeon attempting to save time in this manner may find that the ball tip of the guidewire becomes stuck at the distal end of the cannula.
What is needed is an intramedullary nail design in which a ball tip guidewire can be reliably used during the implantation of a surgical instrument, throughout the implantation procedure and without the need for a wire exchange.